In recent years, a handsfree device in, for example, a vehicle and a mobile communication device such as a cellular phone are connected wirelessly by using BLUETOOTH (Registered trademark) connection or connected by wire for placing and receiving a call. Description in Japanese Patent Document JP-A-2003-298727 discloses the handsfree device that is capable of connecting to the cell phone by using the BLUETOOTH connection.
The cellular phone having subscription to a call waiting service or the like provided by a communication carrier is capable of receiving a second call while being involved in a first call. That is, the first call is held in waiting for picking up the second call, or the second call is held in waiting for resuming the first call.
The conventional handsfree device does not have a specific operation switch for the call waiting service. Therefore, a user of the cellular phone has to switch the calls by operating a key disposed on the cellular phone.
However, the operation of the key of the cellular phone for using the call waiting service is not necessarily convenient for the user, nor distraction caused by operating the key on the cellular phone may not be appropriate while the user is involved in driving a vehicle or the like.